In laparoscopic procedures, surgery is performed in the abdomen through a small incision in the skin. Such procedures typically involve distending the abdominal cavity away from the underlying organs to improve access and visibility, using gas insufflation or a mechanical distension technique. Laparoscopic procedures generally require the surgeon to act on organs, tissues and vessels at a distance from the incision, thereby requiring that any instruments used in such procedures be long and narrow while being functionally controllable from the proximal end of the instrument.
Many different procedures may be performed during laparoscopic surgery requiring the use of many different instruments, such as, ligating clip appliers, staplers, disposable scissors and tackers. Presently, however, no universal handle is available to operate all of these varied instruments. Thus, hospital inventory is increased, instrument costs to hospitals are increased, the number of handles which require cleaning is increased, and the number of instruments present on the surgical tool table is increased. Additionally, the surgeon must become familiar with the operation of each of the different instruments, some of which have a plurality of triggers for actuating the different operating mechanisms of that instrument.
For example, in laparoscopic surgical procedures, it is frequently necessary to ligate ducts, such as blood vessels, or other severed tissues. For this purpose, it is well-known to use surgical clip appliers that advance a clip and clamp a clip, such as that described in U.S. Pat. No. 5,084,057. However, such a clip applier discloses the use of two actuating triggers, one to advance the clip and the other to clamp the clip. The dual trigger clip applier does not provide the ease of use and simplicity that accompanies the use of a single trigger instrument. In addition, the costs of manufacturing such a clip applier are increased since a handle with two triggers requires the additional molding and manufacture of a second trigger, associated trigger parts and additional lockouts.
Known laparoscopic instruments for applying surgical clips and which have a single actuating trigger include those devices disclosed in U.S. Pat. Nos. 5,289,963; 5,192,288; 5,171,249; and 5,171,247. The clip applier of U.S. Pat. No. 5,289,963, however, only has a movable clip advance mechanism, not a movable clamping mechanism. Therefore only one actuating trigger is necessary. The clip appliers of U.S. Pat. Nos. 5,192,288; 5,171,249; and 5,171,247 disclose devices having both movable clip advance and movable clamping mechanisms. The two mechanisms, however, do not operate independently, but rather are operated simultaneously as the trigger is actuated. Also, in each of these three patents, a clip is automatically advanced upon release of the trigger after the previous clip has been clamped. Therefore, the operator has less control of the clip feed and there is a chance that the clip may accidentally shoot out of the device or get caught or snagged by frictional forces so that the clip cannot advance.
In the case of a clip applier, it is also desirable that only one clip be fed into the jaws of the device at a time. For example, in previously known instruments, a ratchet and pawl mechanism was used to prevent the trigger from returning to the clip reload position until the previously loaded clip had been clamped to a duct. In one instrument, described in U.S. Pat. No. 5,289,963, the ratchet and pawl mechanism is mounted to a longitudinally movable plunger that actuates the operating mechanisms. In this case, however, the ratchet and pawl mechanism has the disadvantage of preventing the surgeon from reclosing the jaws of the device should the surgeon desire to confirm that the clip has been properly clamped. In another instrument, described in U.S. Pat. No. 5,192,288, the ratcheting mechanism includes a hooked end of the pawl that engages a grooved path of ridges and cliffs on the trigger. However, this ratcheting mechanism has a complex construction, and it may be unreliable since one must rely on the resiliency of the pawl to engage the grooved path.
It is also desirable in some instances to have a "resposable" instrument, i.e. an instrument having a disposable end effector detachable from a reusable handle. Most laparoscopic instruments are either fully disposable or fully reusable. Single use disposable instruments, however, are often not cost effective, whereas reusable instruments require thorough cleaning and sterilization between uses. U.S. Pat. No. 5,040,715 discloses the use of a detachable end effector having a finger structure for engaging an internal portion of the handle and having a movable sleeve for disengaging the end effector from the handle. However, the finger structure and sleeve make the end effector relatively expensive since additional molding and manufacturing are required. Also, tight tolerances are required to insure a secure fit between the attachment and the handle. Being disposable, the end effector should be as simple and inexpensive as possible.
Other known laparoscopic instruments have attachment devices for connecting and disconnecting various end effectors. However, these attachment devices are typically quick connect attachments that require that a knob be depressed as an end effector is attached. Another commonly known attachment means used with laparoscopic instruments is the bayonet mount. However, the bayonet mount requires an additional rotational motion, and if the rotational motion is not performed, the end effector cannot be securely attached. These attachment devices thus require additional manipulation, such as a coordinated, two-handed movement, to attach the end effector to the handle.
From the discussion above, it should be apparent that there is a need for a surgical apparatus that can be used in laparoscopic procedures and that includes a universal actuating handle for use with a variety of attachments or end effectors and that can convert a single lever motion of the handle into two separate and independent actuator motions. In addition, there is a need for a surgical apparatus that includes a ratchet and pawl mechanism for preventing the return of the actuating trigger so that only one clip is fed at a time, but that permits reclosure of the trigger to insure that the function of the end effector is properly performed. In addition, there is a need for a surgical apparatus having a disposable end effector that includes an attachment mechanism for connecting and disconnecting the end effector to and from a reusable handle that has a simple, secure and easy to use design requiring no additional manipulation or rotational motions, and that is economical and easy to manufacture.